今年，北京将在全国率先执行更严格的机动车国五排放标准，力争在2016年与国际接轨，实施相当于欧六排放标准的新车准入标准，有效控制机动车排放污染。
　　从北京PM2.5主要成因看，与能源消费直接相关的机动车排放和燃煤排放约占总量的40%（各占22.2%、16.7%）。未来较长一段时期，北京空气质量将在连续13年好转的基础上，以降低PM2.5为重点，通过实施一系列的强制性措施，打一场提升空气质量的攻坚战。
　　Beijing will usher in a stricter vehicle emission regulation this year amid public discontent over air pollution, the city's economic planning agency said Friday.
　　Beijing will lead other provinces in the country in implementing the tighter National 5 vehicle emission standard, equivalent to the Euro 5 emission standard applied to passenger and light vehicles in EU member countries, the Beijing Municipal Commission of Development and Reform (BMCDR) said in a statement.
　　All cars sold in Beijing will be required to meet the new standard, according to the BMCDR. The commission did not give an exact timetable for the enforcement of the regulation, although cars that have already been sold will not be required to comply with the regulation.
　　The BMCDR said it hopes to boost the standard by 2016 to make it equivalent to the tighter Euro 6 emission standard.
　　The BMCDR said the move is aimed at "effectively controlling exhaust pollutants from automobiles," as the capital city has promised to reduce air pollution and make other environmental efforts.
　　Beijing's environmental protection authority began to use the PM2.5 air quality standard on Jan 12, as the city's persistent smog has raised health concerns among its residents.
　　The PM2.5 standard is more strict than the previous PM10 standard, as it allows for the monitoring of fine particles with diameters of 2.5 microns or less.
　　BMCDR said automobile emissions account for more than one-fifth of the city's PM2.5 particles.
　　The number of registered vehicles in the city exceeded 5 million this month, indicating that one in four Beijing residents owns a car. The municipal government implemented a license plate lottery system at the beginning of last year to limit vehicle purchases.